The biological effects of ionizing radiation

The biological effects of The biological effects of ionizing radiationionizing radiation

CERN Academic Training CERN Academic Training

27-30 May 200827-30 May 2008

The biological effects of ionizing radiationThe biological effects of ionizing radiation

by Marilena Streit-Bianchiby Marilena Streit-Bianchi

CERN Academic Training Lectures

27th, 28th and 29th May 2008

27th-29th May 200827th-29th May 2008 Marilena Streit-BianchiMarilena Streit-Bianchi

The biological effects of ionizing The biological effects of ionizing radiationradiation

First lectureFirst lecture - Ionizing radiations and radiations units- Ionizing radiations and radiations units - Exposure to natural background radiation- Exposure to natural background radiation - Exposures by medical usage of radiation- Exposures by medical usage of radiation - Biological effects (cellular damage, genomic instability, bystander effects and adaptive response, - Biological effects (cellular damage, genomic instability, bystander effects and adaptive response,

dose response as function of radiation quality, dose fractionation and dose rates effects). dose response as function of radiation quality, dose fractionation and dose rates effects).

Second lectureSecond lecture - Biological effects (some particular effects, tissue reactions: skin, intestine, blood, testis, ovary, - Biological effects (some particular effects, tissue reactions: skin, intestine, blood, testis, ovary,

fetus. Hereditary effects. Lethal doses. Stochastic effects)fetus. Hereditary effects. Lethal doses. Stochastic effects) - Health effects of ionizing radiations on short and long terms, from high and low doses - Health effects of ionizing radiations on short and long terms, from high and low doses

(Hiroshima and Nagasaki).(Hiroshima and Nagasaki).

Third lectureThird lecture - Health effects of ionizing radiations on short and long terms, from high and low doses (Chernobyl, - Health effects of ionizing radiations on short and long terms, from high and low doses (Chernobyl,

radiologists, radon exposures, nuclear workers.)radiologists, radon exposures, nuclear workers.) - Risk estimate from epidemiological data- Risk estimate from epidemiological data - Radiation limits and ICRP recommendation- Radiation limits and ICRP recommendation - Future research on radiation effects.- Future research on radiation effects.


8·054±0·010 days. 8·054±0·010 days. 8·054±0·010 days.

131I Physical half-life

8·0545±0·0063 days.

137 CsPhysical half-life 30.1 years

90 Sr Physical Half-life 28.1 Years


Chernobyl: Site monitor Chernobyl: Site monitor measurement at CERNmeasurement at CERN


Chernobyl: Rainfall measurements Chernobyl: Rainfall measurements at CERNat CERN


Mean effective doses from Mean effective doses from ChernobylChernobyl


Doses to clean-up workers in Doses to clean-up workers in ChernobylChernobyl

From Cardis E. et al 2006


Estimated Thyroid doses from Estimated Thyroid doses from Chernobyl accidentChernobyl accident



Populations in Europe for which Populations in Europe for which epidemiological studies have been epidemiological studies have been

mademade

From UNSCEAR 2000


Acute radiation sicknessAcute radiation sickness (ARS) from (ARS) from ChernobylChernobyl Death of 30 workersDeath of 30 workers.. 237 initially suspected ARS 237 initially suspected ARS

persons,persons, in 1989 only 134 in 1989 only 134

confirmed ARSconfirmed ARS, all are , all are under medical control.under medical control.

internal exposureinternal exposure: : short-lived radioiodines short-lived radioiodines and radiotelluriums, and radiotelluriums, long-lived radionuclides long-lived radionuclides (Cesium)(Cesium)external exposure:external exposure: gamma, beta to gamma, beta to skin and eyes skin and eyes (essentially in recovery (essentially in recovery operation workers)operation workers)

Population (years Population (years exposed)exposed)

NumberNumber Average Average total 20 total 20 years years (mSv)(mSv)

Liquidators (1986-Liquidators (1986-1987)1987)

highly exposedhighly exposed

240000240000 > 100> 100

Evacuees (1986)Evacuees (1986) 116000116000 > 33> 33

Residents Residents (>555kBq/m(>555kBq/m22))

270000270000 > 50> 50

Residents low Residents low contamination contamination

(37 kBq/m(37 kBq/m22))

50000005000000 10-2010-20

Natural backgroundNatural background 2.4 2.4 mSv/yearmSv/year

(range 1-10, (range 1-10, max > 20)max > 20)

4848


Thyroid cancersThyroid cancers after Chernobyl accidentafter Chernobyl accident

From UNSCEAR 2000

Incidence of thyroid cancers in Belarus1986-2002

From Yamashita S. 2006 Demidchik E.P. 2006


Thyroid cancerThyroid cancer in Chernobyl childrensin Chernobyl childrens

85% of children, 3 85% of children, 3 years old or irradiated years old or irradiated in uterus.in uterus.

60% of children 60% of children between 4-15 years between 4-15 years old and 50% of old and 50% of teenagers receiving teenagers receiving 50-300 mGy50-300 mGy

>15000 children born >15000 children born ( 1979 – ( 1979 – 1986)received more 1986)received more than 2 Gy.than 2 Gy.

Age at Age at exposureexposure

Belarus Belarus (1)(1)

Russian Russian Federa-Federa-tion (2)tion (2)

UkraineUkraine

(3)(3)TotalTotal

<15<15 17111711 349349 17621762 38223822

15-1715-17 299299 134134 582582 10151015

TotalTotal 20102010 483483 23442344 48374837

Number of cases of thyroid cancer diagnosedbetween 1986 and 2002 by country and age

at exposure

1) Cancer registry Belarus 20062) Russian National Medical and dosimetric registry 20063) Cancer registry of Ukraine 2006


http://www.chernobyltissuebank.com/


CancersCancers in Chernobyl adultsin Chernobyl adults

1.1. Improvement in diagnosis, reporting and registration may Improvement in diagnosis, reporting and registration may affect the resultsaffect the results

2.2. Some of the studies reported have methodological Some of the studies reported have methodological limitations limitations

3.3. For solid tumour latent period is long therefore too early for For solid tumour latent period is long therefore too early for a full radiological impact evaluationa full radiological impact evaluation““There have been reports of an elevated incidence of all solid There have been reports of an elevated incidence of all solid cancers combined as well as of specific cancers in Belarus, the cancers combined as well as of specific cancers in Belarus, the Russian Federation and Ukraine, but much of the increase appears Russian Federation and Ukraine, but much of the increase appears to be due to other factors, including improvements in registration, to be due to other factors, including improvements in registration, reporting and diagnosis….reporting and diagnosis….In the coming years, careful studies of selected populations and In the coming years, careful studies of selected populations and health outcomes are needed in order to study the full effects of the health outcomes are needed in order to study the full effects of the accident and compare them to predictions”accident and compare them to predictions”

from “from “Cancer consequences of the Chernobyl accident: 20 years on” Cancer consequences of the Chernobyl accident: 20 years on” Cardis E. et al. 2006Cardis E. et al. 2006


CancersCancers in Chernobyl adultsin Chernobyl adults

2 fold increase in breast cancer and 2-7 fold 2 fold increase in breast cancer and 2-7 fold increase in thyroid cancer have been increase in thyroid cancer have been reported.reported.

2 fold increase in non-CLL leukemia between 2 fold increase in non-CLL leukemia between 1986 and 1996 only in Russian liquidation 1986 and 1996 only in Russian liquidation workers exposed to >150 mGy external workers exposed to >150 mGy external dose (Ivanov V.K. et al 2003c).dose (Ivanov V.K. et al 2003c).


Leukemia in recovery operation Leukemia in recovery operation workersworkers

From UNSCEAR 2000


LeukaemiaLeukaemia in Chernobyl clean-up workers in Chernobyl clean-up workers


Recent article on leukemiaRecent article on leukemia

““Empirical studies in affected populations are Empirical studies in affected populations are summarized, and it is concluded that, possibly apart summarized, and it is concluded that, possibly apart from Russian cleanup workers, no meaningful from Russian cleanup workers, no meaningful evidence of any statistical association between evidence of any statistical association between exposure and leukemia risk as yet exists.” exposure and leukemia risk as yet exists.”

From From Howe G. R. 2007 Howe G. R. 2007 “LEUKEMIA FOLLOWING THE

CHERNOBYL ACCIDENT” Health Physics. 93(5):512-Health Physics. 93(5):512-515.515.


Chernobyl B-cell chronic lymphocytic Chernobyl B-cell chronic lymphocytic leukemialeukemia

IGHV3-21 gene expression was found in 11 IGHV3-21 gene expression was found in 11 cases (5.8%) - (frequency intermediate cases (5.8%) - (frequency intermediate between Scandinavian (11.7%) and between Scandinavian (11.7%) and Mediterranean CLL (2.9%) cohorts )Mediterranean CLL (2.9%) cohorts )

Negative prognostic significance of IGHV3-Negative prognostic significance of IGHV3-21 gene expression.21 gene expression.

IGHV3-21 expression was associated with IGHV3-21 expression was associated with development of secondary solid tumors.development of secondary solid tumors.

From Abramenko I. et al. 2007 From Abramenko I. et al. 2007


Reproductive effects from ChernobylReproductive effects from Chernobyl

From UNSCEAR 2000


Immune response ChernobylImmune response Chernobyl1)1) radiation emergency workers exposed to low-dose irradiation during 1986–1989 andradiation emergency workers exposed to low-dose irradiation during 1986–1989 and2)2) nuclear industry workers exposed under professional limitsnuclear industry workers exposed under professional limitsirradiation dose limits of 250 and 100 mSv irradiation dose limits of 250 and 100 mSv Comparison group 42000 personsComparison group 42000 persons

Early responseEarly response:: Immunological deficiency with T-cell subset changesImmunological deficiency with T-cell subset changes Lymphocyte membrane changes and increased lipid peroxidationLymphocyte membrane changes and increased lipid peroxidation

Reconstitution period:Reconstitution period:Inhibition of the immune function associated with lymphocyte subset changes ( decreased CD3+ Inhibition of the immune function associated with lymphocyte subset changes ( decreased CD3+

and CD4+ cells counts and increased number of somatic mutations in TCR-locus). and CD4+ cells counts and increased number of somatic mutations in TCR-locus).

Late response:Late response: decreased CD8+ suppressor cell function that could lead to poor proliferation controldecreased CD8+ suppressor cell function that could lead to poor proliferation control

No dependency of dose–effect type were detected in nuclear industry workers No dependency of dose–effect type were detected in nuclear industry workers

From Bazyka D. et al. 2003From Bazyka D. et al. 2003


Psychological impactPsychological impact

Excess of suicides among the atomic bomb Excess of suicides among the atomic bomb survivors exposed to low doses (0–90 mGy) survivors exposed to low doses (0–90 mGy) (Kusumi et al., 1993). (Kusumi et al., 1993).

Direct dependence between the suicide rate and Direct dependence between the suicide rate and the residency distance from the Atomic Test Site the residency distance from the Atomic Test Site (Alimkhanov, 1995). (Alimkhanov, 1995).

Suicides are the leading cause of death among Suicides are the leading cause of death among Estonian clean-up workers (Rahu et al., 1997). Estonian clean-up workers (Rahu et al., 1997).

From Loganovsky K. 2007From Loganovsky K. 2007


Others non cancers effectsOthers non cancers effectsfrom Chernobylfrom Chernobyl

Cardiovascular and cerebro-vascular Cardiovascular and cerebro-vascular diseasesdiseases

Blood diseasesBlood diseases

http://www.unscear.org/unscear/en/chernobyl.html

http://www.who.int/ionizing_radiation/chernobyl/en/

http://www.iaea.org/NewsCenter/Focus/Chernobyl/index.html

If you want to know more:


Results from some studies in EuropeResults from some studies in Europe FinlandFinland: Monthly dose rate estimated= double the natural background. : Monthly dose rate estimated= double the natural background.

Transient decrease in birth rate not related to the fallout as it had Transient decrease in birth rate not related to the fallout as it had already begun before 1986.Statistically significant small increase in already begun before 1986.Statistically significant small increase in spontaneous abortions in July-December 1986 with dose rate spontaneous abortions in July-December 1986 with dose rate (attributable to unusual low rates in 87 and 88?).From Auvinen A. et al. (attributable to unusual low rates in 87 and 88?).From Auvinen A. et al. 20012001

GreeceGreece: : Leukemia cases since 1980. Infants exposed in utero had 2.6 Infants exposed in utero had 2.6 times the incidence of leukemia compared to non exposed childrens. times the incidence of leukemia compared to non exposed childrens. From Petridou et al. 1996 From Petridou et al. 1996

GermanyGermany: Increase in trisomy 21 in Berlin 9 months after the accident. : Increase in trisomy 21 in Berlin 9 months after the accident. From Sperling K. et al. 1994. From Sperling K. et al. 1994. Greek findings not confirmed by German study. From Steiner et al. Greek findings not confirmed by German study. From Steiner et al. 19981998No evidence of congenital malformation in Bavaria. From Irl C. et al. No evidence of congenital malformation in Bavaria. From Irl C. et al. 19951995

SwedenSweden: Indication of increase in Down syndrom and childhood : Indication of increase in Down syndrom and childhood leukemia that if no random could be related to exposure. From leukemia that if no random could be related to exposure. From Ericson A. and Kallen B. 1994No increase in malformation seen. From De Wals P. and Dolk W. 1990


Data from RadiologistsData from RadiologistsFrom Brenner D. J. & Hall E. J. 2003

SMR=Standardized Mortality Ratio

US survey include radiologist from 1960.British survey include radiologists that entered the field from 1970 (lower doses and shorter follow-up)

Early radiologist estimated annual doses is about 1 Gy/yr (Braestrup C.B. 1957)

The British cohort ,1955-1970, show decrease of mortality compared to control Group(Cameron L.S. 2002 and Daunt S. 2002)


Impact of new technologiesImpact of new technologiesin cancer inductionin cancer induction

10% of 10% of patients presenting at major Cancer Centers have a patients presenting at major Cancer Centers have a second cancer (lifestile, genetic, RT)second cancer (lifestile, genetic, RT)

10-year survival rate for patients treated for breast or 10-year survival rate for patients treated for breast or prostate cancerprostate cancer

younger patientsyounger patients are treated, and with are treated, and with longer life longer life expectancyexpectancy, RT-induced second malignancies will assume , RT-induced second malignancies will assume increasingly greater importance due to Intensity Modulated increasingly greater importance due to Intensity Modulated Radiation Therapy (IMRT) treatmentsRadiation Therapy (IMRT) treatments


Increase on CT scan in USAIncrease on CT scan in USAand attributable riskand attributable riskfromBRENNERandHALL2007

From:Brenner D. J. & Hall E. J. 2007


Estimated risk from CT scanEstimated risk from CT scan

fromBRENNERD.J.andHALLE.J.2007


Radon and lung cancerRadon and lung cancer

From UNSCEAR 2000


15-country nuclear workers study15-country nuclear workers study

(Australia, Belgium, Canada, Finland, France, Hungary, Japan, Korea, Lithuania, (Australia, Belgium, Canada, Finland, France, Hungary, Japan, Korea, Lithuania, Slovakia, Spain, Sweden, Switzerland, UK, USA) Slovakia, Spain, Sweden, Switzerland, UK, USA)

407 391 workers individually monitored for external radiation 407 391 workers individually monitored for external radiation with a total follow-up equivalent to 5.2 million person years. with a total follow-up equivalent to 5.2 million person years.

Excess relative risk for all cancers excluding leukemia: 0.97 SvExcess relative risk for all cancers excluding leukemia: 0.97 Sv-1 -1

(95% CI 0.14, 1.97), for all solid cancers 0.87 Sv(95% CI 0.14, 1.97), for all solid cancers 0.87 Sv-1 -1 (95% CI 0.03, (95% CI 0.03, 1.88). These estimates are somewhat higher but statistically 1.88). These estimates are somewhat higher but statistically compatible with current Radiation Protection recommendations.compatible with current Radiation Protection recommendations.

Lymphocytic leukemia 1.93 SvLymphocytic leukemia 1.93 Sv-1 -1 (95% CI <0, 8.47) close to (95% CI <0, 8.47) close to what previously observed in previous nuclear workers studieswhat previously observed in previous nuclear workers studies

From Cardis E. et al. 2005, Cardis et al. 2007 and From Cardis E. et al. 2005, Cardis et al. 2007 and Vrijheid M et al 2007Vrijheid M et al 2007


In occupationally exposed person in general is In occupationally exposed person in general is common to observe the so called « healty worker common to observe the so called « healty worker effect ». Overall mortality rate is about 15% lower effect ». Overall mortality rate is about 15% lower than in general population. This effect has been than in general population. This effect has been also reported for radiation workers.also reported for radiation workers.

Conclusions from BEIR VIIConclusions from BEIR VII-Health benefit exceeding detrimental effects from -Health benefit exceeding detrimental effects from low doses radiations is unwarranted-low doses radiations is unwarranted-


HBNRsHBNRs

People residing at high altitude level have less People residing at high altitude level have less health problems.health problems.

Considering the population living in Guodong, Considering the population living in Guodong, China population receiving 3-4 mGy have been China population receiving 3-4 mGy have been compared with near population receiving 1 compared with near population receiving 1 mGy/year, no difference was obtained. Excess mGy/year, no difference was obtained. Excess cancer are expected to be only 1-2% above cancer are expected to be only 1-2% above cancers occurring from all causes during lifetime. cancers occurring from all causes during lifetime. How to detect it even if cofounders would be taken How to detect it even if cofounders would be taken into account ??????into account ??????


Are low doses beneficial?Are low doses beneficial?

Adaptive response (< effect DAdaptive response (< effect D11+D+D22 =< D =< D11+D+D22))

Additivity (effects adds up DAdditivity (effects adds up D11+D+D22 = D = D11+D+D22))

Synergistic effects (> effect DSynergistic effects (> effect D11+D+D22 => D => D11+D+D22))


LimitationsLimitations

From E. Hall 2007

.01 .05 .1 101.0 2.5 100

Low Dose Extrapolation

Bystander effect

The Gold Standard:A-bomb Survivors


AssumptionsAssumptions

Induction of gene and chromosomal mutations are important for the cancer process

For low LET radiation (doses of a few mGy and below) linearity of response for targeted events in cells (inherent DNA error-prone repair process for the DNA double-strand lesions as complex clustered DNA lesions are difficult to repair correctly)


Are linear-no threshold (LNT) model good enough for projecting cancer risk to low doses

and low dose rates?

PRAGMATIC APPROACH USED by ICRP 103 and BEIR VII

AS NO BETTER EVIDENCE BASED JUDGMENT IS TODAY AVAILABLE

Contested by French Academy of Science as too conservative


The dose and dose rate effectiveness factor (DDREF)DDREF)

A factor (DDREF) to take into account human exposures at low doses (dose ~ 100 mSv) and low dose rates

Derived from animal data excluding ovarian and thymic lymphoma induction (highly curvilinear threshold-like response)

A factor of 2 at doses < 2 Gy is used by ICRP (ICRP 103) whereas BEIR VII takes as value a factor of 1.5.


Cancer risk estimates from Cancer risk estimates from epidemiological dataepidemiological data

Average sex and age at exposure time Lifetime risk estimates are computed using risk estimates specific to

various cancer sites. ICRP system, estimates are derived for males and females combined

whereas BEIR VII make a distinction between male and female The nominal risks are computed for each site of interest and summed

to give the population total nominal risk The overall site-specific and total nominal risks are computed by

averaging the population-specific average risks. Risk estimate are averaged across Asian and Euro-American

populations Excess relative risk (ERR) or excess absolute risk (EAR) both take into

account sex, attained age, age at exposure Risk and detriments are calculated for whole population and working

age population (18-64 years)


0.1 Gy radiation cancer estimates 0.1 Gy radiation cancer estimates in 100000 peoplein 100000 people

( ) 95% Confidence LimitsSolid cancer estimate based on Linear model and Reduced Dose and Dose-Rate Dose and Dose Rate Effectiveness Factor (DDREF) = 1.5

(from: BEIR VII)


New ICRP recommendations – New ICRP recommendations – Biological aspectsBiological aspects

1.1. Tissue reactions (dose modifying factors 1.1 to Tissue reactions (dose modifying factors 1.1 to 2) 2)

2.2. Cataracts and cardiovascular disease need Cataracts and cardiovascular disease need more accurate risk evaluationmore accurate risk evaluation

3.3. wwRR and w and wTT for stochastic effects have been for stochastic effects have been revisedrevised

4.4. LNT model (and DDREF of 2) retained as LNT model (and DDREF of 2) retained as prudent practiceprudent practice

5.5. Heritable effects/multifactorial diseases have Heritable effects/multifactorial diseases have been considered in more detailbeen considered in more detail


Genetic RisksGenetic Risks They They are loware low probably as the genetic changes compatible with probably as the genetic changes compatible with

embryonic development and viability. Essentially embryonic development and viability. Essentially multigene deletions

Considered for 2 generations onlyConsidered for 2 generations only Most chronic diseases have genetic component, but are Most chronic diseases have genetic component, but are

multifactorialmultifactorial

Doubling dose=amount of radiation required to produce as Doubling dose=amount of radiation required to produce as many mutations as accounting in one generationmany mutations as accounting in one generation

Spontaneous 3 mutations/million people/generationSpontaneous 3 mutations/million people/generation

20 cases per 10,000 people / Sv

Previously in ICRP 60 (100 cases / 10,000 / Sv)


Recommended radiation weighting factors wwRR for stochastic effects

(ICRP 103 2008)(ICRP 103 2008)Radiation type Radiation weighting factor, wR

Photons 1

Electrons and muons 1

Protons and charged pions 2

Alpha particles, fission fragments, heavy ions

20

Neutrons A continuous function of neutron energy (see Fig. 1 and Eqn. 4.3)

MeV50,25.32.5

MeV50MeV1,0.170.5

MeV1,2.185.2

n6/)04.0ln(

n6/)2(ln

n6/)(ln

R2

n

2n

2n

Ee

Ee

Ee

wE

E

E

(4.3)

ICRP 60


Cancer risks and tissue weighting factors have been calculated for 12 tissues and organs (oesophagus, stomach, colon, liver, lung, bone, skin, breast, ovary, bladder, thyroid, and red bone marrow). The remaining tissues and organs have been grouped into ‘remainder’


Recommended tissue weighting factors wwTT for stochastic effects

(ICRP 103 2008)(ICRP 103 2008)Tissue

wT ΣwT

Bone-marrow (red), Colon, Lung, Stomach, Breast (was 0.05) 0.12 0.72 Remainder tissues* (was 0.05)

Gonads (was 0.20) 0.08 0.08

Bladder, Oesophagus, Liver, Thyroid 0.04 0.16

Bone surface, Brain, Salivary glands, Skin 0.01 0.04 Total 1.00

* Remainder tissues: Adrenals, Extrathoracic (ET) region,Gall bladder, Heart, Kidneys, Lymphatic nodes, Muscle, Oralmucosa, Pancreas, Prostate (M), Small intestine, Spleen, Thymus,Uterus/cervix (F).


ICRP 103 Recommendations ICRP 103 Recommendations (2008)(2008)

LNT model and DDREF of 2 retained, as previously saidLNT model and DDREF of 2 retained, as previously said The possibility that there might be a threshold dose, below

which there would be no radiation-related cancer risk, has been not upheld

Adaptive responses to radiation – the animal studies do not provide sufficient evidence of reduced adverse health effects to be taken into account for radiological protection

Epigenetic phenomena - not sufficient proof of their influence on cancer risk (differential contribution to risk?)

Heritable effects and multi-factorial diseases to be Heritable effects and multi-factorial diseases to be considered more in detail considered more in detail

Genetic risks expressed to 2Genetic risks expressed to 2ndnd generation, 0.2% per Sv generation, 0.2% per Sv


Cataracts, cardiovascular diseasesCataracts, cardiovascular diseases

Lens:Lens: 150 mSv/year occupational, 15 mSv public 150 mSv/year occupational, 15 mSv public

Cataract threshold dose 1.5 Gy (ICRP 60)Cataract threshold dose 1.5 Gy (ICRP 60)New evidence suggests threshold <100 mGy New evidence suggests threshold <100 mGy (haemangioma treatment in childrens (haemangioma treatment in childrens (Hall E.J. et al. 1999),(Hall E.J. et al. 1999), A- A-bomb survivors bomb survivors (Minamoto A. et al. 2004),(Minamoto A. et al. 2004), Chernobyl) Chernobyl)

Heart:Heart: Not yet included for threshold doses, but could be Not yet included for threshold doses, but could be around 1 Gy. around 1 Gy.

From A-bombs and Chernobyl non-cancer diseases From A-bombs and Chernobyl non-cancer diseases becoming more recognised as important.becoming more recognised as important.


Nominal risk coefficients/100/Sv Nominal risk coefficients/100/Sv at low dose-rate ( ICRP 103 and previous ICRP 60)at low dose-rate ( ICRP 103 and previous ICRP 60)

Cancer Heritable effects Total Exposed population

Present1 Publ. 60 Present1 Publ. 60 Present1 Publ. 60

Whole 5.5 6.0 0.2 1.3 55..77 7.3

Adult 4.1 4.8 0.1 0.8 44..22 5.6


Limits (in agreement with current ICRP recommendations)

Type of limit Occupational (CERN) Public (CERN)

Effective dose 20 mSv / year 1 mSv / year

Annual equivalent dose

lens of the eye 150 mSv 15 mSv

skin 500 mSv 50 mSv

hands and feet 500 mSv -


In your interest, rememberIn your interest, remember Pregnancy has to be announced to medical Pregnancy has to be announced to medical

service as soon as known.service as soon as known.- Person taken away from working in controlled - Person taken away from working in controlled

radiation areas. radiation areas. - Max dose allowed during pregnancy equally - Max dose allowed during pregnancy equally

dose to the public (1 mSv)dose to the public (1 mSv)

Children are forbidden to stay in radiation Children are forbidden to stay in radiation controlled areascontrolled areas

Accidents or near misses to be announced Accidents or near misses to be announced immediately to RP or Medical Serviceimmediately to RP or Medical Service


Assessment of dose Assessment of dose after an accident or a suspected accidentafter an accident or a suspected accident

Physical dosimetry (personal dosimeter, area monitors, dose Physical dosimetry (personal dosimeter, area monitors, dose reconstruction and reconstruction of accident)reconstruction and reconstruction of accident)

Medical examinationMedical examination Blood analysis (including chromosomal aberrations for Blood analysis (including chromosomal aberrations for

biological dosimetry) biological dosimetry) In case of possible contamination risk: whole body counting In case of possible contamination risk: whole body counting

(at HUG, Geneva)(at HUG, Geneva)

Others possible bioassay or dosimetry to Others possible bioassay or dosimetry to reconstruct doses but not of standard usereconstruct doses but not of standard use

Tooth enamel (Electron Paramagnetic Resonance dosimetry)Tooth enamel (Electron Paramagnetic Resonance dosimetry) HairsHairs


More research is neededMore research is needed Molecular biomarkers to quantify low level of DNA damageMolecular biomarkers to quantify low level of DNA damage DNA repair fidelity at low level of radiation damage and mechanisms DNA repair fidelity at low level of radiation damage and mechanisms

of error-prone repair of radio-induced lesionsof error-prone repair of radio-induced lesions Damage in stem cell spermatogonia and oocytes as well as in various Damage in stem cell spermatogonia and oocytes as well as in various

tissue stem cellstissue stem cells Dose-dependence of post-irradiation cellular signalling, its implications

for estimating DNA damage and cancer risk at low doses Genomic instability and bystanders effects at very low dose-rate and Genomic instability and bystanders effects at very low dose-rate and

after fractionated exposuresafter fractionated exposures Roles of DNA repair processes in the origin of deletion in germ cellsRoles of DNA repair processes in the origin of deletion in germ cells Identification of regions prone to radiation deletionIdentification of regions prone to radiation deletion Do hormetic effects exist for radiation induced carcinogenesis?Do hormetic effects exist for radiation induced carcinogenesis? Role of radiation in multi-stage radiation tumour-genesisRole of radiation in multi-stage radiation tumour-genesis Genetic factors in radiation cancer riskGenetic factors in radiation cancer risk Future studies on medical exposures (i.e. epidemiological studies in Future studies on medical exposures (i.e. epidemiological studies in

children exposed to CT exams, follow-up of radiotherapy patients for children exposed to CT exams, follow-up of radiotherapy patients for secondary tumour induction)secondary tumour induction)

Environmental studies (accidents)Environmental studies (accidents) Continuation of follow-up on occupationally exposed peopleContinuation of follow-up on occupationally exposed people

Documents

The biological effects of ionizing radiation